Реферат: Development Of Computers And Technology Essay Research

these improvements was built in 1947. This group included computers using

Random- Access-Memory (RAM), which is a memory designed to give almost constant

access to any particular piece of information. . These machines had punched-card

or tape I/O devices. Physically, they were much smaller than ENIAC. Some were

about the size of a grand piano and used only 2,500 electron tubes, a lot less

then required by the earlier ENIAC. The first-generation stored-program

computers needed a lot of maintenance, reached probably about 70 to 80%

reliability of operation (ROO) and were used for 8 to 12 years. This group of

computers included EDVAC and UNIVAC, the first commercially available computers.

Early in the 50’s two important engineering discoveries changed the

image of the electronic-computer field, from one of fast but unreliable hardware

to an image of relatively high reliability and even more capability. These

discoveries were the magnetic core memory and the Transistor – Circuit Element.

These technical discoveries quickly found their way into new models of digital

computers. RAM capacities increased from 8,000 to 64,000 words in commercially

available machines by the 1960’s, with access times of 2 to 3 MS (Milliseconds).

These machines were very expensive to purchase or even to rent and were

particularly expensive to operate because of the cost of expanding programming.

Such computers were mostly found in large computer centers operated by industry,

government, and private laboratories — staffed with many programmers and

support personnel. This situation led to modes of operation enabling the sharing

of the high potential available. During this time, another important

development was the move from machine language to assembly language, also known

as symbolic languages. Assembly languages use abbreviations for instructions

rather than numbers. This made programming a computer a lot easier.

After the implementation of assembly languages came high-level languages.

The first language to be universally accepted was a language by the name of

FORTRAN, developed in the mid 50’s as an engineering, mathematical, and

scientific language. Then, in 1959, COBOL was developed for business